The present invention relates to optical communication systems and more particularly to interconnections among optical communication equipment.
A site in a service provider optical network such a metro or core DWDM network will typically have a variety of optical modules including, e.g. transmitter modules, receiver modules, multiplexer modules, demultiplexer modules, amplifier modules, etc. These modules are interconnected by optical patch cords. There is thus often a confusing jumble of such interconnections. Installation of equipment and provisioning of new services required disconnecting and/or connecting one or more optical patch cords. Due to human error, optical misconnections can be quite frequent leading to loss of existing service and delays in provisioning new services.
A known method of verifying optical connections is to embed electrical wiring in each optical patch cord and then use the electrical wiring to transmit a coded signal that verifies the proper connection. One of the connection modules transmits a coded signal that identifies that device or the connection. At the other end of the connection, the other device detects this code to verify that the correct connection has been made.
This approach, however, carries drawbacks. The electrical patch cord effectively acts as an antenna, radiating electromagnetic interference (EMI) into electronic boards on either side of the link. The use of isolators as EMI shields is only a partial solution to this problem and comes at greatly increased cost.
What is needed are systems and methods for verifying optical connections without introducing electromagnetic interference.